SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae88e556882f31290505f3918d59d340825b02d653e19d8b86ca9b0bf4cae943' 
  AND token = 'TYdv25/4WR5PRpa5qBPIrAjnNd+Be3rAqIumJWbpeSw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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