SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2233b87009dba2e19863b2668aa189332681bca8546287c1f5010b1dbe413e8' 
  AND token = 'Yce4uvlLi6GdwyWSgD6SgESDAgPG3ODpLeigXEhCKI8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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