SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa18ffebdedccabe6cc10f98dc62fabcb207970fd490f8505b7930917aef4686' 
  AND token = 'DVCCUsazxS4usV6iZn8G3CJi0E2NO4w3bgGrw4LLRr4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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