SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab30f88203f7beb01150ff18184ba38837616c349bf98c859549c088ab3e5eb0' 
  AND token = 'liCJXfXfkleLEJLp3ny+Uz/ZatvlnHLeIK4lXruZ89M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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