SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd4fbe065d3452119926ca72303b7584fe87531dd9e9b46ae45c09315b7c2ce7' 
  AND token = 'CW8bQ/TmQQSYbfJBVk+sQuJArj/NxzEbcKpOCKUGIAw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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