SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e46c291d738c08d6bd55dee482cb085663f1416d691336cfef6634c370208a6f' 
  AND token = 'I4zVPA01tNklGrw0QkuGMiQGEqUREpAVx1jEptSuN5c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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