SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b10e38f46a7554b8a6adfb6ff1000f229cc45c9560355678e8aa95b030e7bf33' 
  AND token = 'i5doLsRW1kbI3eNjBldGw+7vbU/FqZhlBsqS84DJpz8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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