SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '980608e92fa23f5cf3579a1f5e30ee0fdc7c4fe7b67c48a49e4213339d6c8401' 
  AND token = '4kwhAR5fGgzwVNTpz4G8Twldp6EXXryYUG5ZJ0jgR2Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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