SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '90dc5aeeea5319c126053679feac575c446a0ed7441bddf2c3baee208dcf160b' 
  AND token = 'xtJleuVdDrAlQCyXccu+82ZXNIwymrXO/EuyvYwaV+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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