SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8118a22968dd948256161c8c94b96a292a6fd2f08dfe4de04d976ec0fed413f' 
  AND token = 'rCLtR7Zu1blKbdyVUQzsx9S/As57NZrH1sUFsdeaZ3Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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