SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ceb616ae8457cd4e887d001b09dbc8913fb9d0637cee241f7f4113a61ede2814' 
  AND token = 'LjU3Lgz1jyMwBsZxuldNW3BBiwVC8YfKHRr7gjjPlfs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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