SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09a794b8706550da3e8272c47ece2263ad51ee8108999562e7cb7d623d6305cd' 
  AND token = 'V3ZlizSvr2NQ5M6gKxcQ6m+m7iI2+AWTmyr+MsHDK3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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