SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c25b6cb8f96d7b0ae695dd7a57b6db0d8d6c7706826405b40211feca3e3a5344' 
  AND token = '5Rb/TMFtkEg3JS5fYkoPPjouznB8pzXzkelz3braHhU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}