SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70492ba467f3db6607137f5bf4511efa77f72ef4a114b73835b5e1e949fb40c5' 
  AND token = '/En52tShFGJNPtHXloGr94gKhVYDtXUcawwbgG3zdoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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