SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77da1fa8a62854944b7cc4557dc2e7ad668aa3ea5dc6f4647c7f0a33a9f123c0' 
  AND token = 'iobJ58u0i6IAmY3/gaHxbNze9U6TDh9nhnHTJX28mFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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