SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9331e015edfbe842936fb412ad0cdea280333c8ae4a40878d1d6abcf86c8ce9' 
  AND token = 'gUCGxIBBnJGNMdhoUDihhP8CIirkFGxVhHEpG4ZmW4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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