SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60d2155608013643673e02fc91e41faa11c866c821709979a273172c60abcdcb' 
  AND token = 'tUMdOru+6nvEuv8kWKMVsyj/rS4/Ffw5g7CWK/uxYJs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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