SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04d74d55f3f3474c2ede29941371cb562c84e6947d2ddea85aafd8075244e9b1' 
  AND token = 'ISdY7FRpAlBMHFLQqSIHlEuFoxTvHFSTkI9OWuj4rCM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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