SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b08a666a811caae7295f939ab1bc114fb6a6462476446a179149be49329922ae' 
  AND token = 'UO3zOVZGb59nB1Apek3l2ahasXiCywtxQ7dvBNmeLDc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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