SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cad583b0493427dc795f87df6d4a58e23da20a07afee1a4d83a75a6c3dd00fcc' 
  AND token = 'O6hYPHvSkXtR3k3o3qawcNanvGy807upZr7vZGiZZXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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