SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2bfdc62a232a7ce945278140a3a5ad21df0af2b0051a7016756db56ddbebd99' 
  AND token = 'gNpJXqHWNtC/tp6hjxugICg4wDOWbMzC6/IUs1UerFo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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