SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18aa5c45d2b3dd7394b80655394813e82ed5ec31bfb80f5c8e78c1685625ad5b' 
  AND token = 'zBCD2DtDp6+p5gH86LhUtTXsjiQaEdZW5UhweioIyic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00075

JSON explain

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