SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1f580d717744ea19a91db186a33d2eb734fbf09b5c7efc962536f2f417d2b39' 
  AND token = 'vtMroBu50asdOBEJu8KbSFmsVVDtZ6yT0/Vv0SmTVog=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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