SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29bc9e693ff07148f42b2b17dbf55bd10c4f8b08a7f6736d8c37a12e06037f31' 
  AND token = 'HgtY2d6FVKtL9+PMbiBB0Z0RQxc/JMYdfC8wCFPwypQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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