SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3207b64f111ded5aeb7478f48c80f7d67d9c3bed522d2463b524d92f423d13c0' 
  AND token = '5ljH5B0ITWbXGXmFQORiqB2o1sYcHE7eGSvHFFbzVps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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