SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16c65454008af5171c40f505bb163ff4ab5c5405c02fd57530276c4bd92b632f' 
  AND token = 'usnfv/b7kSHKdZeX/+7eqSGKORiVXmIJVMHthhbcAww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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