SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e0fd80bb1393ac0cb2967a32eac583ecfebeb3550f6162062eeb1c115ebdb60' 
  AND token = 'V+vbygy36KM1L9gX/ajeYhZ+XcgTwwBs+HdBU6LwZmg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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