SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b2834889467c98c3f66d0bf598d90ccca4b5a8626819c06dddd2ce654dfbb13' 
  AND token = 'UTwoWpgWbH22P1ZEag0L3GJXE6RLrXRIB18IvvZ8ZbU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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