SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa19eda0583f5d7aa1c98857fb204153de15762e366a7501f49de2389f2f0958' 
  AND token = 'Qs5LwgcBsK9w/ZQl9hpccC5jSCS5LStTZ6r5267r6E4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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