SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d7a35f59b4e4d5195aa98344e7015fedf47df16138049f7a2a3e17def1d8198' 
  AND token = 'JZ64GUiYcNgijqORQntlqYJMoVYjpEY8PxI0j1mPstw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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