SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fae9be566a4a7996f917867d254d630188c36adab5522b13ef609bec0ee4a825' 
  AND token = 'kRcZ7RNVMTwz4DMcWGsjlNG26wEaGeyf4GirJP79CdU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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