SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd254e77f0988fd6c72f604a90d0444f44c5c6124971f49e9417ed11530212ba2' 
  AND token = 'AXqIqmn8oeaUb57VWs0CwHIQxUkMcloj+C+xXBzBbLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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