SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '646f0a0e353f9cc87d888c619b4872695ecaa43ecd507ef4b82b3e1b21f85368' 
  AND token = 'WIp10HY1FhO/JVBH8ZWhcCDybqq0lqzu9Pw2QG/8Vis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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