SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbc45ceccdf48d22e23c88529ce9a2f211a2372e1aae06df5278a008810ce8bd' 
  AND token = 'paAZUgUIvnt2yv1OWfnDTKqmzCDV+Faj8NhS6nF7E9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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