SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afa0a64d3fb694af46d552bef113ac5a7fe4ddaf761b278e142abb8f84d97a40' 
  AND token = 'BwwhO+1CpYi/XJBoR+WqjQ7qrr27k+2O0JyX9DdFGHE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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