SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '887fd1b79ccaa0a4488348f0c7ba216302e24448b909741054b71ce99e55f14d' 
  AND token = 'M8b2ojNnWygTCRsECqru2DT36P4vX30kFonCIMItZAo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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