SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b725101721447dc3afb1a45fd89d9a19792cda7a8b52189230ec88e2d54be683' 
  AND token = 'TwO117578uzom9n9HXgwv773nJiW2qpjYVflW+pVGFY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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