SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c14b428fcf31524dac25bc2bcacc439e9bb073df49dd2add1b0ef80917ab706' 
  AND token = '9mYj8I8gTAYmVVq5zHugQMnmC9G02UIBHmB2Wc1YLn4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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