SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a95c2ac7be22200fc862d0279df5d2d2b851c5c5e817194106bf9b48ddb8d6f' 
  AND token = 'RJf5K2yjG5jsa52UV1QIdJLmEMYpIr1kWiiixWCQD1w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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