SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f659390f305667145afe4051330fa170fdd3dd94243738238b2d34cd3ee17ae' 
  AND token = '+tH/a4OBHPVuXP3nNEdhDS+OmoCfOE2zS4kghLk3HD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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