SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66ba695122d6f5042cfb0f3d8f00a1316095859296a10f75109ba4b33aa5d78f' 
  AND token = 'ScWTNIHBZENZmkXBk51wAhp7caFS3nAXX/EiB1DyBLk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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