SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5dac056c282db66aae3f4099ba6a585a41fb6b022c53e68dd6cca7e64a138743' 
  AND token = 'V3JtQzvXG/r6InptPvhpDpVgd/CtrTTZsgpTE+lIw+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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