SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c5162424d12d79e843c24148f178ca747a0f6325a264b2b312ac0b39dfd256a' 
  AND token = 'gZ3nNHGugI3Nry9VCqhVWg8R3Igx5JwKJI3+eKKoqGE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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