SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7828ba7eabaddf50043b5914706ed283c4db7829a73794d0bf9a27270f771beb' 
  AND token = 'tpjSf8vHvwvOuH/btD/dH+ZkO+b+Q6339v17SWcpqps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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