SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae13c52be95b5c3a5838630a91c46578df85a3e73e3022fc6eccf1789326eeb8' 
  AND token = 'syJRDOVN6G9dUeg1BiqJfWJbdWhuI+CPEpJSiVJzC3M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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