SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '631e64151a3383ee50eb5e90e4df89b71d4c0f279623e339a2636e38640fd18a' 
  AND token = 'AOuoUTWRY2V0Pr9Jn/AJ7Z7IsNHhjKCMJwQZQSLYpa0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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