SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2544a7807c1d72ad08447a367dfbce26b5d57bc6bd5210757f0714962adbad2b' 
  AND token = 'PXDMzXt1cCLU5ni4/GLqpBugWEmjMrXnwG5hIrG9ikg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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