SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b77b849e25d730ee2301116b88522b4869384c79c21ee9662bbdc96b54658746' 
  AND token = 'BNzTPjdSMQRBZulpHrIIcH/sbVAOWzr2DgEmHXpiZHU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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