SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c8722882af5ae5605c523f512ae17f26a2d5e698866f4a7ffae10b16b89c509' 
  AND token = '7B7ASUvQ9F9VgQuGl0A//XCs/xDiLFB7kXNjCJGI+mQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

JSON explain

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