SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a87e9d21102cc264290eb4422e6ace4ead793f56a1cafc5702b4e16a74aead4a' 
  AND token = 'WX3Tzazb958icm+7fSlFtJZ8F6S+lerY7QtnYDa8O5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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