SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d9a3bf611b4a416a4d3e12671ca2474617702133d0be3cd60b2a1a91c77df37' 
  AND token = 'PQQHDjrXogWHUqcu+OfrGQpqj+ge84jD6sV6Ja5Rtaw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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