SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a93cd776a2313a22a871c73de677755e2226e5c4b72a1451f08f6a994eede87' 
  AND token = 'fungIVvUJXPmc4F4fwNGAzVQ51ydAJYgGDfESfp380s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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