SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a53857de63fa9ae31218c6414ef6276b43a9918f233594a78803e0613e703b39' 
  AND token = 'yqGA17RdU7epViwliFSE28Ujp286LJx8nrzFZ0N/LXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}