SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2de88176bc1ab36b7ba2b2fd31cad11091225ff992dc305d762a011196d8a5fe' 
  AND token = 'j9EprvNbkrD6yKM6AUFkITvMMz56qazIYjAbyMDdskg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}