SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee9385b831b79b165302dc42497dc087e0ed951be6cb8448824660d9a08bc238' 
  AND token = 'R8MSlsgoa+EgOutviCdtZ3wW/Ncyp4w9o7dr9eWnhgs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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