SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35d20486a18475e0ede449d2cb93edc88514fdac2f71d43f8f4a9801312d4ef0' 
  AND token = 'M15EfqpjH8lQKr2bu/u4EhNRu5MC9iiR+vxPRyzX0bk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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