SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '013626faa82b971f7618f6090d65084161508af8e82e0b753a2b96879cdc7ec2' 
  AND token = 'HZ1VTQ1adOuGR8lzwkZuRBMUX5OOV+YypGJLbRmDEj4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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