SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fba55578ce2a98d7493971a786f96192fcc13bcd7186ccce0cc5988656d8328d' 
  AND token = 'LKhu1fGcj6pJtrdmKcJ8t5QAIsO4fPQtwwafqoa4y9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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