SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f140ed656f22dc62434603b6095a8267a8d3309de559a173c226b4a62a0a9789' 
  AND token = 'HyFf9oPHmFH/cE9rVMTYzMjncMjwSCjhZPbo4b4G0Cc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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