SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64ac92f685462448f4cd5d15fc0d4c448d8b65f3011bfc3b3ea890fe13045c2a' 
  AND token = 'nnq7ToxiEmRYBG7slvPHh4tE/LvGK4JNg4uLV7gLFBI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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