SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b632999f85be56edc69678702a4f676b2165ae8d484fdbd030824e18c05903a4' 
  AND token = 'hV8jhtukacb8gpbIK+mOZqysp/GPi9biBTwUkn8pxgQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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