SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0a3fd63e7c6fb501f0cc928ffc5ec5fc7c956bb2d72c0305e7de5fa247463ab' 
  AND token = 'Im3Aag6TFOrHWN3B9vVt2Ezk9HqnMqHaYfkA/DhGQA4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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