SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a920ab6b81fd9405982e79eacc681fccf88770386be413082001889779c1e85f' 
  AND token = 'ZASAc8dckAj1peIYhnTWJ9IxZUh7swDjjYJ61WLZhfA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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