SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db0e2e9d3dc0ef30656df202908b0eb0bc4041fb727a20b3515c1e4d4bba7acf' 
  AND token = 'ikh3zRCYkaEusOwkfP5NemtV4DEgE2kJemU9ACnX6aA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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