SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '073439c0171824cc9edae030ae9133a412563fb3c1e70d3c2536c7d7ae3d178b' 
  AND token = 'fijF/ZGhVQKyq460xJ/EJHydpbyZRkwlyF9hiIfug+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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