SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d50a097bf8d3d7480042eabc420759fb0fa139f29a9aeb111a57a2ec3ae8cdf' 
  AND token = '9SprsdF5+ALKbE43enWVsX+HFvmBCsWGHN12LyKsuRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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