SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0643068fad89df8f324b270903f2cad0518a30f8e25495cd35e75096a617d767' 
  AND token = 'TbyJIlD38pgAH/zkjV/x4iaD/OoCcLcBklLhx8UXJ/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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