SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80f12d617bb0224180e7edd9ee8f6b76cd90412abf90b41436feae0076286c62' 
  AND token = 'W4WuNEJGPNNu3XuLmmeui6PUgHTk5WwfDAmvDIWDfTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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