SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '612a7794870e01f3b88e10e6852ac4a7ed66b26b48238d12988254369fb9cd5b' 
  AND token = 'pcygaimZGvIoVK+b6NYHjHFTGhMvLUHeJULoXBqiHSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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