SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6705325f5940f98b051fca68cd0ac9e6c682e860f0387df0e073ddf6905f55d9' 
  AND token = 'NnGbtVBBLJZKGjzGQTiw32PhvN5RWlYIkuNR8VKfiss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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