SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b83332bb82b08ba56de6982fee3652e42ede1695aaf661bcb9f244fd0a807bd0' 
  AND token = 'b7BzMfzpJgJA0TwimksOQ9zgQKwgYaFCxaTX4/QWqy4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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