SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cccdd8411ac7d1446777d2024826471f5c57bca64fec9121f2c70949717ecd8c' 
  AND token = 'sihWHjKYNQs300J6KSjNwvb7nzT5cys/olWKIiUOJxI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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