SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41cb4175fdaa9e373276bed345e8d88743c3a1743335f782cc238b8660d3e243' 
  AND token = 'UH0hwPj/B1AO2NqnLiqr62RfL6udABwKvO4oGMudMEE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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