SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3cf83e56e85848a2fccccb4556cfb72cd0437a01d96c5afb107360d904fa8761' 
  AND token = 'cY8cuZxksmqexnXQ/Mft3zhflNWvg2LXTyxwevK33Ws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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