SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebab038ba74cf2cfef84cbf93aba736259db4a3cdfd1154295c21454d0516e71' 
  AND token = 'ISrNCLWs2ZPet/cwlMinElHfVpV8/P0xlNgANqzFK1E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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