SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc4a337124fa2f27d69a34337267179e50597fa52eed7dfb4e707e30f1d9c75a' 
  AND token = 'eMqxVErDA1k/2CrrFILpe1aWZeaif9Kw2zPWBbsQOlM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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