SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fe86d33bd25b5d16dd8bcc8ac544f74ca7880de67b711979da992425ab565da' 
  AND token = 'uZ4rzd+iQk8OFYMvBTDSc4utJFkYVuOXiRaHHq+/pxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}