SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bddd39f71c3b84ec2c8372536dce69ecbe0e8695f74fd455ad936cf672f746c5' 
  AND token = 'rVU/LjJZIEWS6fiSAOG2GFhm9+g1DJnY6rMSuL+q+0M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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