SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa9f0ee9eb0044485911f318e74a84d63e4b707d4ca1b46ba1bdc3cfa4c34ad6' 
  AND token = 'dMzrCMPMCaOW1aJJzXcu6lnevzfsVkzMuM7glgBGxqM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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