SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b563ffc4580cd8463772880d5bda4fb03e0d2d3c1997696ab245d116dfc2110' 
  AND token = 'w/5aYYw+38qV9qmu4mDghNo/xHILUvb8MA9AcYy3Beo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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