SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '557279447a4abc780515bccc4fa19be33a067a8899190c0862892be31071c0e6' 
  AND token = 'R3MGkX18Duq29/jHCFvfeYIgTFzfg6AuYxTBunnGw74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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