SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b0c58d3eadb78731010f915b14c785844dda1d14123d0329e4272ef164a74d4' 
  AND token = 'whUonJCsHYRRSs5MgUjH49JNHoQPASKHJRzpGYxTZOg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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