SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f806a31aba4bdf40b8fe48139d893f385a3b7a918c5cbeefacda2a18f497a5a1' 
  AND token = 'ol5XSOSFqG0NONxc/+8ht6n63cuFe9dyFMXEEpGnfZc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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