SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6464fccfca9d4af0ac3a004969cce17052d49a4b92eef9bdef94a34612deeb67' 
  AND token = 'MBd7ZXgPD8aAE2m2355BDk7Y2xlxbMyPYkBq7yOsS4s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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